Project Summary Pertussis and influenza are the most poorly controlled vaccine preventable diseases in the United States. Pregnant women have increased risk of severe disease from influenza and newborns have increased risk of severe disease from influenza and pertussis. The Advisory Committee on Immunization Practices and American College of Obstetricians and Gynecologists recommend women receive influenza and pertussis (Tdap) vaccine during each pregnancy, yet only about half of pregnant women receive these vaccines. Among identified barriers to maternal immunization are patient concerns about vaccine safety and effectiveness and lack of evidence for how ob-gyn providers can best communicate vaccine recommendations. Interventions to address these barriers and increase uptake of maternal immunizations are urgently needed. Motivational interviewing (MI) is a communication technique that has proven effective for changing health behaviors including increasing adolescent vaccination rates. MI is both time-effective and acceptable to providers. The long-term goal of this project is to adapt MI to the ob-gyn setting to improve influenza and Tdap vaccine uptake in pregnancy. There is evidence to support use of MI for childhood immunizations; however it is unknown if MI is feasible and acceptable among ob-gyn providers and pregnant women. We propose a pragmatic practice-based study in 5 Colorado ob-gyn practices to develop the MI for maternal immunizations (MI4MI) intervention and assess acceptability, adoption and implementation among patients and providers. Aim 1 will use an iterative process building upon existing knowledge of patient concerns about maternal immunizations and our prior experience training providers in MI for childhood immunizations to develop the MI4MI training. During development, we will conduct focus groups for provider input and [organizational context. The MI4MI intervention will include a video-module, in-person training, provider reference sheets, and practice study champions. Aim 2 will include intervention implementation and assessment of MI4MI acceptability, adoption, and implementation. We will audio-record a sample of provider visits with patients with vaccine concerns to assess fidelity of the intervention. Audio-elicitation interviews will be conducted to assess acceptability of MI4MI among patients. This qualitative method uses a recorded interaction to guide a semi-structured interview. We will conduct post-intervention provider focus groups to assess acceptability and adoption of the MI training intervention. We will also conduct pre- and post-intervention surveys among providers to assess time spent and self-efficacy in vaccine communication. Providers will receive Maintenance of Certification or Continuing Medical/Nursing Education credit for participation. In Aim 2a, we will conduct pre- and post-intervention chart reviews in study practices to evaluate the impact of MI4MI on influenza and Tdap vaccine uptake in pregnant patients. This study will provide data for a larger implementation study with rigorous assessment of the effectiveness of MI4MI in increasing maternal immunization uptake in the future.